Timer



Nov. 19, 1946. c. w. SMITH 2,411,393

TIMER Filed Jan. 15, 1946 3 Sheets-Sheet l INVENTOR Char/9s WSW/1%.

BY M5. 6 4

ATTORNEY C. W. SMITH Nov. 19, 1946.

TIMER Filed Jan. 15, 1946 3 Sheets-Sheet 2 mJ W 8 k f m Pu ATTORNEY Nbv. 19, 1946.

c. w. SMITH 2,411,393

TIMER Filed Jan. 15, 1946 3 Sheets-Sheet 5 I INVENTOR C/mr/ss W 6/77/77 ME WU- ATTORNEY Patented Nov. 19, 1946 UNITED STATES TIMER Charles W. Smith, Sharon, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application January 15, 1946, Serial No. 641,375

11 Claims.

During exercise runs of a torpedo, it is extremely important that a torpedo does not sink and thereby make recovery diincult or impossible and that the torpedo does not go beyond the range set.

During exercise runs of a torpedo, the exercise head-corresponding to the war head for war shotsis filled withballast water, or some other cheap liquid, which must be expelled, that is, blown from the exercise head to make the torpedo buoyant. For reasons well known, a torpedo is normally so loaded that it has a negative buoyancy. vTo efiect surfacing of a torpedo at a desired'time, the'ballast liquid is expelledfrom the exercise head to cause surfacing of the torpedo. The most desirable time for effecting such surfacing is just prior to the end of the exercise run, but if for any cause whatsoever the torpedo does not complete its normal exercise run, it is essential to cause surfacing of the torpedo while it is still in. motion.

With the electrically propelled torpedo now 7 generally used, the blowing of the exercise head is usually effected by admitting carbon dioxide gas into the exercise head from a high-pressure CO2 flask.

' One object of my invention is to effect surfacing of a torpedo at the desired time.

Another object of my invention is the provision of means that effect the unfailing function. of the means for causing the blowing of the ballast liquid from the exercise head of a torpedo when the operating conditions are such that the torpedo should surface to facilitate recovery of the tor-,

pedo.

A more specific object of my invention is the provision of means for effecting the unfailing function of timing means so' devised that the ballast liquid is expelled from the exercise head of a torpedo just prior to the end of the exercise run, or prior to the expiration of such time if the operating conditions are such as to make surfacing of the torpedo desirable.

It is also an object of my invention to prevent the'possibility of a torpedo making an exercise run of greater range than the range set. r Another not so specific object of my invention is to eliect surfacing of a torpedo a definite time after firing of the torpedo, or prior to the expiration of such definite time period should the torpedo speed decrease to a given speed or some other operating condition of the torpedo make surfacing desirable.

Other objects and advantages of my invention will become more apparent from a study of the following specification and the accompanying drawings, in which:

Figure 1 diagrammatically shows so much of the circuits of an electrically propelled torpedo as are necessary to illustrate some features of my, invention;

Fig. 2 is a vertical sectional view of parts of my invention taken. on section line II-II of F 3;.

Fig. 3 is a top plan view of the timers with the cover in place;

Fig. 4 is a sectional top plan view on section line IVIV of Fig, 8;

Fig. 5 is a fragmentary sectional view of the top portion of the timer mechanism and illustratingone of the reset buttons, or stems, mounted in the top cover;

. Fi 6is a sectional view on lines VI--VI of Fig. 8;

Fig. 7 is a sectional View on line VII- VII of Fig. 8;

Fig. 8 is a vertical sectional view of parts taken on line VIIIVIII of Fig. 4 with some parts broken away;

Fig. 9 is a bottom plan View of parts with the cover in place.

My invention embodies an improvement of the subject matter shown in the copending application of Charles C. Whittaker, Serial No..592,803, filed May 9, 1945, and entitled Control system.

The clearest concept of my contribution to the art can probably be had from a study of the operating sequence of the subject matter shown in Fig. 1. The details of the timing mechanisms will be described below after the discussion of Fi 1.

When the torpedo T is fired from the firing tube I, the trigger valve 2, through the operation of lever 3 by the dog 4 on the firing tube is operated to connect the gas pressure flask 5 to the conduit 6. This conduit is connected to the valve 1' which is latched to the open position by the latch mechanism ll.

With valve .1 in the position shown, gas pressure is admitted to the pneumatically operable switch 8. This switch, with a time delay of about three-fourths of a second, closes the contacts 9,

Q) whereupon a circuit is established from the positive terminal iii of the battery B through the motor armature of motor M, the field windings F, and contacts 9 to the negative terminal if. of the battery.

The pneumatically operable switch is of the type disclosed and claimed in the pending joint application of Charles C. Whittaker and Ruel C. Jones, Serial No. 559,077, filed October 17, 1944, and entitled Controls.

Per se the switch 8 forms no part of my present invention, but in the combination herein disclosed this switch 8 functions to close contacts 9 with a sufficient time delay to. assure u 'the torpedo is well clear of the louvers atthe front of the torpedo tube. Rotation of the propellers livided to prevent sticking of the armature. In so doing, the spring 22 is released, and the bar 23 P is thus delayed just sufficiently to prevent rotating contact of the propellers with the louvers. A time delay of a half to one second is usually selected. This time is ample for the torpedo to clear. the tu-be..

. In the equipment with which my invention has actually been used, the time constant of switch TBIhas been so adjusted that the contacts 9 close 7 after a delay of three-fourths of asecond after 7 the firing of the torpedo.

.Since the firing of the torpedo producesan acceleration of approximately 1 M3, use ismade is rotated clockwise on the shaft I l. The instant the torpedo acceleration ceases, spring it starts the "armature rotating counterclockwise about pivot l6,but such rotation is retarded because the pa'wls 24 engage wheel 25 fixed on shaft 14. A torque is thus applied to shaft it, but its counterclockwise rotation is slowed to a constant speed by the inertia elements of the clock mechanism l3. The actuating coil 28 is connected across the field windings F of the motor. A short time after the closing of the contacts 9, the voltage drop across the field F is built up sufliciently to energize coil 28. j The circuit for coil 28, may be traced from junction 29 through conductor '35], coil 28,

of this accelerating force toset, the timingmechanisms in operation. It sometimes happens that .this, accelerating force f ails to set the timing mechanismin operation,- The causesmay be any one of several, as for instance, the accelerating force may not suffice, certain. elements operated i by an inertia member responsive to acceieration 'may sti'ck, both of these mentioned causes may ,be present, or someother cause may be present. 'My invention is concerned with theelimination of these causesof improper operation. q, The timer mechanisms include .two distinct clock mechanisms one, ,namelylihfor producing jashorttimedelay, and asecond, namely 36, for producing a ,longer. time ',delay. The timer l3 per se is of well known design and includes an -inertia gear train. 7 When a torque is applied to its actuating shaft I l, (see Figs. 4 and 8 this a .timer it through the inertiaelements of its gear train, permits rotation of shaft M at a constant speed for as long asa torqueis applied tdthis .{shaft Us The timeof operationof.v shaft it is selected at about two to three seconds.

Torque is applied. to this shaft by the armature l5 pivoted at it on the U-shaped bracket l'i ,rigidly secured to the insulating plate it fixed pn-the timermechanism frame. The'armature l 5 ,is biased for ,counterclockwise ,(clockwise in Fig, 1 rotationby the tension spring l S hooked to the backv end of the armature and the frame,

as shown most clearly in Fig.8. The armature es a, h -2i)- mounted in the torpedo so thatthe bottom ther eof is directed aft of the: torpedo. Acceleration The timer mechanism is of the torpedo through the inertia of weight 2E thus causes the armature E5 to move clockwise ('counterclockwisein Fig. l) aboutits pivot U5.

The right;hand end of the, armature is provided witha clip 2i having at its extreme right end an ,upwardly directed hook engaging the left-hand leg of. the U-shaped upper end of the leaf spring 22. This leaf spring at its base is secured to the frame and is .biased to move:toward the right once released by the hook on the clip 2l.

. .The right-hand end of the armatureis, by

means of .linkQZE, operatively connected to the, bar iiiloos'ely mounted on the shaft M. The bar conductor 31, contacts 32 and 45, conductor 33, contacts li} and 5E conductor 35, to other side of F and contacts 9 to the negative terminal 12 .cf the, battery B. The full energization of coil 28 thus occurs a moment after acceleration of the torpedo ceases and while the armature I5 is in its initial stages of its counterclockwisemovemerit, The armature is thus again, but now elecjtromagnetically, moved clockwise andwill remain in contact with the horizontal surface of guide 2? aslong as coil 28 remains energized.

The second timing device or clock mechanism utilized is also initself in part of well known design and includes a .clock spring for driving itstiming elements. 'I 'he spring of this timing device is wound by a, suitable key attached to the shaft 31. Another shaft 61. (see Fig. 8) operable by the clock spring, not shown, is provided ,with. a gear 38 meshing with a gear sector 39 f xed on a sleeve shaft 88 which is rotatably distion sector 4!. i mounted at E3 andis so biased that it frictionally posed on shaft 40.

The gear sector 39 is rigidly secured to aifric- A leaf spring 42 is pivotally engages the friction sector 4! byan axially directed force. Any clockwise movement of the friction sector M, as seen in Figs. 6 and '7, causes counterclockwise movement of the leaf spring 42.

The pivot bloclgg l for. the leaf spring 42 is of insulating material. carrying the leaf-spring con'tact 45., Any relatively small angular move- .ment of the leaf spring in a counterclockwise direction, will thus cause contact 45 to engage resilient contact fi disposed on asuitable block of insulation 46 mounted on the frame on the timing device. It will thus be apparent that setting of timing device 35 presently to be discussed and involving clockwise movement of friction secthecam 41. 'This cam"41; when the timer is in its full zero' position, as shown 'in Fig. 9 and Fig.

:7. is in such aip o sition that the carnlsurface t8 moves the resilient "contact '49 sothat'it'is out leaf spring 56 fixed to the frame at 51.

'4 and 5.)

5 .of contact with contact 50 but is in engagement with contact 5|.

When the exercise run is to be made by the torpedo, the shait 68 is turned thus actuating friction sector 4| and this operation carries leaf spring 42 counterclockwise to thus cause engagement of contacts 32 and 45. The shaft is turned until the index 52 on cam 41 is opposite the number selected on the adjacent dial 53.

It will be noted that the graduated sector or 'dial 53 carries numerals running from to 10. This simply means that by suitable manipulation of the key on shaft 31, the index 52 may be brought adjacent any one of the numbers on the dial 53. The number selected indicates, for normal operation, the time in minutes after firing of the torpedo that the ballast liquid is to be expelled from the exercise head.

If the index is moved opposite number 8 on the dial 53, then the cam region is well out of the way of the actuating end of the resilient contact 49, and contacts 49 and 50 are in engagement.

The second timing device or' clock mechanism 36 is set in operation by depressing the button 54. A weight 55 is mounted directly above this button 54 and is biased away from the button by the The leaf spring 56 carries the weight 55. The weight 55 is provided with a notch 58 coacting with the downwardly directed leaf spring 59. (See Figs. The sprin 59 is fixed at its upper end to the relatively rigid bracket 69 secured to the frame.

Upon firing of the torpedo, the weight lags the movement of the torpedo and thus actuates the button 54. The leaf spring immediately moves into the notch 58 and the weight 55 and thus the button 54 "remains in the actuated position. The timing device is thus set in operation and continues to operate until a short time after the index moves opposite the zero reading on the dial 53.

7 An instant after the torpedo is on its way, the

timing device 36 starts the movement of elements 39, 4| and 41 in a counterclockwise direction. (See Figs. 6 and '7.) A relatively short time-a half'minute or somewhat lessthe leaf spring .42 is moved clockwise an amount sufilcient to 'open the contacts 32 and 45. The current limitvoltage changes after firing of the torpedo.

The right-hand end of the armature I5 is provided with a contact 6| disposed to engage con tact 62 in the event coil 28 is for any cause deenergized.

,II the operation of all the elements is normal.

namelyasexpected, then after the lapse of eight minutes of torpedo movement through the water, the cam portion 48 engages the actuating end of the resilient contact 49, thus causing a break between contacts 49 and 50. Disengagement of these contacts interrupts the energizing circuit for coil 28 at these contacts.

The armature 5 is thus released, and the spring 19 moves the armature counterclockwise. "The'speed of movement is, however, retarded by "the timing device l3 since the pawls 24 engage 1-.wheel 25- to rotate the gear train for actuating the verge escapement of this timing device or clock mechanism l3.

After the lapse 'of four or five seconds at the most, contacts 6| and 62 are brought into engagement. As soon as these contacts engage each other, a circuit is established from the positive terminal of the battery through contacts BI and 62 to conductor 63, the squib 64 of the CO2 flask 65, conductor 66, and contacts 9 to the negative terminal of the battery B. The CO2 flask gas pressure is thus admittedto the exercise head and the ballast liquid is ex pelled from the exercise head. It will be noted that the expulsion of the ballast liquid takes place-or at least is well underway-while the torpedo is still in motion.

Some ten to twenty seconds after the contacts 49 and 59 move out of engagement, the resilient contact 49 engages contact 5| whereupon a circuit is established for the latch release coil for the valve. The circuit is from the positive terminal l0 through coil 69, conductor 19, contacts 5| and 49, conductor 35, and contacts 9 to the negative terminal of the battery.

This valve thus moves through with a snap action. The pneumatic switch 8 is now connected to the timing leak device 1|. This device is described in considerable detail in the hereinbefore mentioned pending application. It sufiices to state in this application that the timing leak device l| permits the gas pressure acting on the pneumatic switch 8 to leak away at a selected speed. When the pressure acting on pneumatic switch 8 decreases to a selected value, contacts 9 are opened with a snap action and the motor is thus disconnected from the battery. The torpedois thus stopped and may be readily recovered since normally by this time it is also buoyant.

My device is, however, not limited to the normal functioning of all elements. If for any reason, when the torpedo is fired, power fails to be applied to the driving motor, the coil 28 is deenergized and as a consequence the contacts 6| and 52 are closed. The ballast liquid is thus immediately expelled even though the cam 4'! has by no means moved to its zero position.

If, after the torpedo starts in a normal manner, some difiiculty develops during the run so that power to the driving motor is interrupted, coil 28 becomes deenergized and the device functions to expel the ballast liquid.

Also, if, after the torpedo starts in a normal manner and the power supply radually fails, the device functions to cause the torpedo to surface before it has lost suflicient speed such that it would start to sink.

Since the clock mechanisms must be useful for repeated exercise runs it is very desirable to provide simple resetting means and means for effecting operation of the clock mechanism 36 independent of firing of the torpedo.

For independent starting of the clock mechanism the actuating stem 12 is used. This stem projects through the top cover and has a lower end projecting through a guide opening in the bracket 73. A biasing spring 14 is disposed on the stem- 12 and is disposed between the bracket 73 and a shoulder 15 fixed on the stem 12. The spring 14 thus biases the stem upwardly so that its lower end, which terminates directly above weight 55, is out of contact with weight 55. By

depressing stem 12 the weight 55 and stem 54 is ,c

actuated in the same manner as if the inertia of weight 55 were to actuate stem 54.

The just described operation presupposes no errors in the functioning of theelements actuated by the weight 55. If the weight-5.5 does not perform its intended function, the-button 54 is'not actuated and in consequence, the clock mechanism 35 is not tripped. The torpedo motor M will not be deenergized at the :end of the range for which the exercise run is set but will continue to operate until the batteries have been discharged completely causing the torpedo to run far-beyond its set rangewith the possible loss of the torpedo and almost certain damage'to some of the equipment in the torpedo. With my contributionno such loss .of the torpedo and damage of its parts ispossible. This will become clearer presently.

If, for any reason, the weight 55 fails to actuate the button 54 then some other and additional means should be provided to effect the operation of button 54. To this end, I mount a solenoid I55 on the front face, or cover, IIll. This solenoid has an armature IBZ-provided with an upper or forwardly' projectingend I53 for manualactuation of the armature IE2. Thearmature I82 is provided with a shoulder atthe upper region.

The lower or aft end ofarmature I52 rests against a forward projection I54 of the stem 72. Thebiasing spring 7 disposed on the stem I2 between the shoulder "I5 on the stem and the bracket I3 biases the projection against the armature I02.

The lower end of stem 12 terminates directly above the weight 55 when in the position shown in Fig. 2. Since the spring-"Hus disposed under suitable compression between the bracket I3 and shoulder I5, it is apparent that stem I2 will be biased against the cover Ill I andin turn will bias the armature I82 to the position shown in Fig. 2.

The acceleration of-the torpedo takes place over the length of the firing tube, and normally weight 5.5. will effect its functionduring this period. If, foriany reason, the weight 55 does not move as intended, the button 54 remains unactuated. The proper functioning of the clock-mechanism 35 now becomes the burden of the solenoid IEO. To the upper surfaceof weight 551 secure a strap Ill! having the contact br-idgingupper end IE8. If the weight 55 did not operate by inertia, then the contact bridging end N38 is retained in position to maintain contacts IiiSclosed. Since the contacts 9 of switch 8 close the instant the torpedo is clear of the firingtube, namely, the moment acceleration ceases, it is apparent that a circuit is establishedfromthe positive battery terminal I!) through 'conductor l'lil, the actuating coil III of the solenoid. Ifillcontacts I55, conductor'I I2, and contacts 9'. to the negative terminal I2-ofthe battery 9.

The energization oftheactuating coil I I I drives armature I 52in the aft directiondownwardly as seen in'Fig. 2'and in consequence actuates stem 12 against the weight 55. The Weight 55; is thus rotated clockwise until clip 59.retains th weight 55, and thus button 54 in the actuated position. Not only is the timer 35 set when the leaf spring I5! is operated but the leaf spring II)? also actuates the contact bridging end I55 to open the circuit forthe actuating coil III -at contacts I59. The coil I I I. canthus not. interfere with the normal functioning of the timer 35 once it is set since the spring I3 immediately moves the stem I2 and thus armature 152 back to'theposition shown in Fig. 2.

If the weight 55 functions as intended, it is, of course, apparent that contacts .lll9will openat or before contacts 9'; close and my auxiliary safety feature is not called upon to perform itsfunction.

The armature I52 is provided with theforward projection I03 so that the timer .36 can beset manually. This .is .important during trials and tests of the circuits.

If both clock mechanisms have completed their cycle of operation, the leaf spring 22 is'out'ofengagement'with theclip H and spring 59 is disposed in notch 58.. Button'l'fi'constitutes the reset button for both weights 2c and 55, this button is spring biased upwardly to a given position. The inner, or lower, end isprovided with a bracket TI having actuating arms I8 and I9 and-a heel portion for actuating armature I5 and. leaf springs 22 and 59 respectively. When button 16 is depressed arm 18 engages clip 2| to thus move the armature I5 downsufficiently so that the upper U- shaped end of spring 22 can be moved over the hook on clip 2i. At substantially. the same time arm I9: engages the right-hand surface of, spring 22 placing the spring 22 inthe position shown'in Fig. 8. The heel portion .Bllengages spring 59 tomove it toward the right to thus release the weight 55 so that the spring 56 carrying this weight moves the weight to the position shown in Fig. 5. When the button is released it moves to the position shown in Figs. 5 and 8 but thearmature I5 and weight 55 remain in the positionshown in. Figs. 5 and 8.

While I have shown but oneembodiment of'my invention, I do not wish to be limited to the specific showing made but wish to be limited only by the scope of the claims hereto appended.

I claim as my invention:

1. In an electro-mechanical control system'for controlling-the buoyancy of an underwater device normally having a negative buoyancy, in combination, a chamber in the device containing a ballast liquid, a'fiask containing gas under pressure mounted on the device for connection to the chamber containing the ballast liquid, electric means for establishing fluid, communication between the chamber and flask, a pair of electric terminals normally energized at a substantially constant potential, electromagnetic means,v responsive to the potential of said terminals, for energizing-said electric means upon a selected decrease in the potential across-saidterminalstiming means, means responsive to the operation of placing the device under water for setting said timing means= in operation, and electromagnetic means, responsive to a failure of'the operation of said last named means for also setting. said timing means in. operation, said. timing means being operableto automatically effect. a decrease in potential across. said terminals 'sufliciently, after a selected time period, to effect deenergization of. saidrfirst named electromagnetic means to thereby eiTect the energization of said electric means.

2. In an eleetro-mechan-ical control system'for controlling the buoyancy of a torpedo normally having a. negativebuoyancy and normally being launched with'acceleration over a relativelyshort timeinterval, in combination, achamber in said torpedo containing a ballast-liquid, a flask containing gas under pressure mounted in the tor pedo and disposed to-be connectedtosaid chamber to expel.theballastliquid therefrom, electric means for establishing fluid communication betweenv the-flask and chamber, 'a'pair of electric terminalsnormally energizedat a'constant potential, electromagnetic means connectedto said terminals and. operableon a selected'. decrease of the potential of. said terminalsto energize said electric means,- timing means inertia responsive means operable-by the acceleration of the torpedo 'during launching for setting said timing means in operation, electromagnetic control means operable upon failure of proper operation of said inertia responsive means for setting said timing means in operation, said timing means including means operable a selected time interval after the timing means is set in operation for decreasing the potential across said terminals sufiiciently to deenergize said electromagnetic means to thus effect energization of said electric means.

3. In an electro-mechanical control system for controlling the buoyancy of a torpedo normally having negative buoyancy by the inclusion of a ballast liquid, normally being fired from a firing tube with considerable acceleration, and normally including means for expelling the ballast liquid from the torpedo when it is to be made buoyant, in combination, a source of electric potential, a timing device, means responsive to inertia and thus normally operable during torpedo acceleration to set said timing device in operation, electromagnetic means. connected to said source at the end of the accelerating period of the torpedo, for also setting said timing device. said timing device including means for effecting the operation of said means for expe ling the ballast liquid a selected time interval after the timing device is set.

4. In an electro-mechanical control system for controlling the buoyancy of a torpedo normally having a negative buoyancy and normally being launched with acceleration over a relatively short time interval, in combination. a chamber in said torpedo containing a ballast liquid, a flask containing gas under pressure mounted in the torpedo and dis osed to be connected to said chamber to expel the ballast li uid therefrom. electric means for establishing fluid communication between the fiask and chamber, a pair of electric terminals normally e ergized at a constant potential. electromagnetic switching means, a torpedo propulsion motor, trigger means operated during the initial stages of torpedo acceleration for connecting said electromagnetic switching means to said terminals, said e ectromagnetic switching means having a time limit just sufficient so as to connect said propulsion motor to said terminals at the end of the accelerating period of the torpedo, a short-time timing device,

siderable acceleration, normally including propulsion equipment set in operation the instant the torpedo clears the firing tube, and normally including means for expelling the ballast liquid when the torpedo is to be made buoyant, in combination, a source of electric potential normally of constant value, means responsive to a predetermined drop in potential of said source of electric potential, regardless of the cause of such drop, for effecting the operation of the means for expelling the ballast liquid from the torpedo, a timing device, means responsive to inertia and thus normally operable during the accelerating period of the torpedo for setting said timing device, electromagnetic means, including movable armature, connected to said source of electric potential at the end of the accelerating period for the torpedo, for operating the movable armature to set said timing device, said timing device including means for effecting the operation of said means for expelling the ballast liquid a selected time interval after the timing device is set.

6; In an electro-mechanical control system for controlling the buoyancy of a torpedo normally having negative buoyancy by reason of the inclua long-time timing device, inertia responsive means for setting said short-time timing device during launching of the torpedo. electromagnetic means, energized by the switching means, for holding said short-time timing device in set position, inertia responsive means for setting said long-time timing device during launching of the torpedo, solenoid means including a movable armature energized by the operation of said switching means for also setting said long-time timing device, said short-time timing device being operable, when released b the electromagnetic device, to energize said electric means to thus eifect connection of the flask to the chamber, and means operable by said long-time timing device for deenergizing said electromagnetic means in a given interval of time and deenergizing'said electromagnetic switching means in a longer interval of time.

5. In an electro-mechanical control system for controlling the buoyancy of a torpedo normally having negative buoyancy by reason of the inclusion within the torpedo of a ballast liquid, normally being fired from a firing tube with con-- sion within the torpedo of a ballast liquid, normally being fired from a firing tube with considerable acceleration, normally including propul sion equipment set in operation theinstant the torpedo clears the firing tube, and normally including means for expelling the ballast liquid when the torpedo is to be made buoyant, in combination, a source of electric potential normally of constant value, means responsive to a nredetermined drop in potential of said source of electric potential, regardless of the cause of such drop, for effecting the operat on of the means for expelling the ballast liquid from the torpedo, a timing device, means responsive to inertia and thus normally operable during the accelerating period of the torpedo for setting said timing device, electromagnetic means, including a movable armature, connected to said source of electric potential at the end of the accelerating period for the torpedo, for operating the movable armature to set said timing device, said timing device including means for effecting the operation of said means for expelling the ballast liquid a selected time interval after thetiming device is set and including means for deenergizing the prop-ulsion equipment a greater time interval after the timing device is set.

7. In an electro-mechanical control system for controlling the buoyancy of a torpedo normally having negative buoyancy by reason of the inclusion within the torpedo of a ballast liquid, normally being fired from a firing tube with considerable acceleration, normally including propulsion equipment set in operation the instant the torpedo clears the firing tube, and normally including means for expelling the ballast liquid when the torpedo is to be made buoyant, in combination, a source of electric potential norma ly of constant value, means responsive to a predetermined drop in potential of said source of electric potential, regardless of the cause of such drop. for effecting the operation of the means for expelling the ballast liquid from the torpedo, a timing device, means responsive to inertia and thu normally operable during the accelerating period of the torpedo for setting said timing device, electromagnetic means, including a movable armature, connected to said source of electric potential at the end of the accelerating period for the torpedo, for operating the movable armature toset said timing device, a projection on said movable armaturefor effecting manual operation of the armature to set said timing device, said timing device including means for effecting the operation of said meansfor expelling the ballast liquid a selected timeinterval after the timing device is set.

8; In an electro-mechanical control systemior controlling the buoyancy of a torpedo normally having negative buoyancy by reason of the inclusion within the torpedo of: a ballast liquid, normally being fired froma'firing tube with considerable acceleration, normally including propulsionequipment set in operation .the instant the torpedo clears the firing tube, and'normally including means for expelling theballast liquid when the torpedo is to be made buoyant, in combination, asource of electric potential normally of constant value, a-timing device, means respon sive to inertia ancl'thus normally operable during the accelerating period of the torpedo for setting said timing device, electromagnetic means, including amovable armature. connected to said source of electric potential at the end of the torpedo accelerating period, for operating the movable armature to also set said timing device, said timing device including means for effecting the operation ofsaid-means for expelling the ballast liquid a selected time interval after the timing device is set.

9. In an electro-mechanical control system for controlling the buoyancy of a torpedo normally having negative buoyancy by reason of the inclusion Within the torpedoof a ballast liquid, normally being fired from a firing tube With considerable acceleration, normally including propulsion equipment set in operation the instant the torpedo clears the-firing tube,- and normally including means for expelling the ballast liquid when the torpedo is to be made buoyant, in combination, a sourceof electric potential normally of constant value, a timing device, means responsive to inertia and thus normally operable during the accelerating. period of the torpedo for setting said timing device, electromagnetic means, including a movable armature, connected to said sourceof electric potential at the end of the acceler-ating period for the torpedo, for operating the movable armature to also set said. timing device, said timing device including means for efiecting the operation of said means for expelling the ballast liquid a selected time interval after the timing device is set and including means for deenergizing the propulsion equipment a greater time interval after the timing device is set.

10. In an electro-mechanical control system for controlling the buoyancy of a torpedo normally having negative buoyancy by reason of the inclusion withinthe torpedo-of, a ballast liquid, normally being fired from afiringtube with considerable-acceleration, normally including propulsion equipment set in operation the instant the torpedo clears the firing tube, and normally including means for expelling the ballastliquid when the torpedo is to be made buoyant, incombination, a source of electric potential normally ofco-nstant value, a timing device, means responsive: to inertia and thus normally operable during the-accelerating period of the torpedo for setting said timingdevice,;electromagneticmeans, including. a movable: armature, connected to said source of electric potentiallat the endof theacceleratingperiod for the torpedo, for, operating the movable armatureyto also setsaid timing device, a'projection on said-movable armature, for effecting manual operation ofthe armature, to set said'timing device, said timingdeviceincluding means for, effecting the operation of, said means for expelling the ballast liquid, a selected time interval after the, timing deviceis setland including means for deenergizing the propulsion equipment a greaterv time interval after the timing deviceis set.

11. In-an electro-mechanical,control system for controlling the buoyancy of a: torpedo normally having negative buoyancy. by reason of the in clusion within. the torpedo of a ballast. liquid, normally vbeing fired from a firing tube. withlconsiderable acceleration, normally including propulsion. equipment set in. operation the instant thetorpedo clears the firing tube,.and normally including means for expelling the ballast liquid whenthetorpedo isto be, made buoyant, in combination, a source of electric potential normally of. constant value, means responsive to a predeterminedvdropvinpotential-of said source of electric potential, regardless-of thecause of such drop, for effecting the operationof the means for expelling the-ballast. liquid, from the torpedo, a timing device, means. responsive to, inertia and thus normally operable during the accelerating period of the torpedo ior setting said timing device, electromagnetic means, including a movable armature, connected to said source of electric potential at the end of the accelerating period for. the torpedo, for operating the movable armature. to set said timing device, a projection on said movable armature for effecting manual operation, of. the armature to set said timing device, said timing device including means for efiecting the. operation of said means for expelling the ballast liquid a selected time interval after the timing device isv set and including means for deenergizing the propulsion equipment a greater time interval after the timing device is set,

CHARLES SMITH. 

